I tend to think of the OT as the core story of Star Wars, and so anything that’s come out since then is supplemental to that core story. You watch the main storyline, then if you want to see more stories that build off of that foundation, you can optionally check out the PT, ST, or EU. All of those things “orbit” around the OT.
For me they are What If stories or High Budget Fan Fiction movies i loved the Prequels as a kid and i enjoyed the Sequels but i prefer the OT more